Electrohydraulic operating mechanism



. Nov. 14, 1933. 1.. s. BOURST I 1,935,432

ELECTROHYDRAULIC OPERATING MECHANISM Filed April 29, 1952 Fig. L

Inventor;-

- Lawrence 5. Bou'r'st, b His Attorney.

Patented Nov. 14, 1933 r UNITED "STATES PATENT ol-f'FlcE leases:

mc'raonrnmmuc orans'mlo luncnsmsls My invention relates to an'electro-hydraulic draulic operating mechanism with the cover operating mechanism and is an improvement broken away of Fig. 1; and Fig. 3 is a cross-secpresent invention.

a is operated, the piston in response to the dedeveloped over the type described in the copending applica- 'tion of my electro-hydraulic operating mechation of William J. Woods, Serial No. 485,474, filed. nism taken on the section line 3-3 of Fig. l. September 30, 1930, now Patent Number 1,901,-

620,, and assigned to the same assignee as the as oil having a pump mounted in the lower end In mechanisms of the above type a vertical 5 thereof. The impeller of the pump isdriven by ceiling or cylinder containing a fluid such as oil means of an electric motor mounted on the cover In the preferred embodiment of my invention, 00 I provide a vertical casing containing a fluid such has mounted therein a piston which moves beof the casing. 'I'he intake to the impeller hous tween two positions within the cylinder and is i'ng extends upwardly through thepiston. The

biased to one of these ositions. An impeller .l i to s ou ted t-hereon-pushrods extendine type, pump having intake and elihaust passages through the casing and supporting a work engagcommunicating with opposite-sides oi! the piston ing crosshead. The piston is biased to a position is mounted at one endoi the casing and forces adjacent the pump and is moved upwardly-in 70 fluid irom'one side of the pistonto the other side p n to Pr ev p by the P mp h of the piston to move the same within the casing. fluid is taken iro'mabove the piston and forced The pump is driven by means of an electric motor to the under side of the piston. When'the motor mounted on top of the casing. When the pump driving k andthe piston returns to' its biased veloped pressure difl'erentlal' is moved from the position forcing the fluid back through the pump biased position to another position and when ir lnhe und r Side 1 e P1 1 to h pp operation of the pump is stopped, the piston re- Si 01 h pi nturns to its biased position. The piston is con-' 1n orderto retard mov m nt of he pi n-fr m nected by means of push rods extending from i s Operating p iti n t it biased p n. I 3

provide a baiile plate which cooperates with the exhaust or the pump and which is biased to parthe casing to a cross-head carrying a work-en- 8881 18 member. v I

In some applications or this electro-hydraulic tially close the exhaust I is fre to m v operating mechanism it is desirable to control the an open position when pressure is developed by p particularly the pressure head developed rate 01' movement of the piston in either or both h Dump that it not ai'fectth Pressure directions-and to vary this rate, and to do this d velop d by the p m vw the motor is without aliectingthe characteristics oi the pump, energized and the piston returns from the oper- It is a principal object of my invention to prothe pump is deenergized, no pressure is ating position to the biased position, this baflle I vide an electro-hydraulic operating mechanism member moves to partially close the exhaust to in which the rate of movement of be controlled and in either direction or both i of urse. reta ds th moveme of the D directions. ton to biased position. The biased position of It is another object of my invention to provide he baiile plate may be varied by means oi an an electro-hydraulic operating in anism in adjusting screw or rod connected to the belle the piston my limit the flow oi fluid back through the pump.

which the rate of movement of. the p on may be plate and extending through the cover. This controlled in either direction or both directions Varies th fluid flew and h n th mil of movewithout aflecting the characteristics of the pump, men} 1' th pi f i l h P n 1 by the biased position.

I In order to vary the movement of the piston pump. 7 V V during its power stroke from its biased position It is still another object 0! my invention to provide an eleetro-hydraulic o erating mechanism in which the rate of movement of the piston in either direction or both directions may be varied.

These and other objects will appear herein-,- aiter. p

Beferring to the drawing, Fig. 1 is a crosssection of my improved electro-hydraulic operat I 'ing mechanism taken on the section line 1-1 0: Fig. 2; Fig. 2 is a; top view of my eleoti-o-h' to its operating position, I provide another adiustable baflie plate cooperating with the intake pressure developed by th e by the pump at all times. Therefore, regardless of the quantity of fluid pumped by the pump from one side of the piston to the other, the pressure developed by the pump will not be affected. It will be seen, therefore, that the only effect of increasing or decreasing the flow of fluid through the pump will be to increase or decrease the rate of movement of the piston within the Referring to the drawing, in Fig. 1 the fluid casing 16 has mounted therein the piston 11 which is shown in its biased position adjacent the pump housing 13. The pump housing has mounted therein the impeller 12 which develops the pressure for raising the piston. The pump housing is provided with-the intake 14 connected with the inlet oil tube 15, which is connected to the bearing bracket 16 supporting the inlet member 17 connected to the oil tube. This bracket member 16 is connected to the cover 18 of the fluid casing 16. The impeller 12 receives oil on both sides through the openings 19 and 20 and expels the oil through exhaust passage 24.

The impeller pump 12 is mounted on the shaft 21 supported in bearings 22 and 23. The hearing 22 is supported by the pump housing and the bearing 23 is supported by the cover 18. The shaft is connected to the electric motor 35 by means of the coupling 36, the motor being supported on the cover 18. by legs 37. A cover 38 is provided for the motor and has ventilating openings 38 therein.

ifhe pump housing has concentric therewith a sleeve 35 which cooperates with the exhaust passage of the pump to form an annular exhaust outlet passage 26 surrounding the pump housing. Resting upon this sleeve and cooperating with the exhaust passage is a baffle plate 2'7 which is biased toward a closed position by means of the spring 28 mounted on the stud 29. The plate is maintained in a partially opened position by means of the rod 30 supported by the cover 18 at 32. This rod may be adjusted in a vertical direction to vary the opening between the plate 27 and the exhaust opening 26.

When fluid is forced through the pump from the upper side of the piston to the under side of the piston to raise the same the plate 2'? is free to move against its bias in an upward direction in response to the pressure developed in the fluid and this prevents retardation of the flow of fluid to the under side of the piston. When the piston resets, however, the plate returns to its partially closed position and limits the flow of fluid back through the pump. This, of course, retards the return of the piston to biased position.

Mounted adjacent the inlet member 17 is a' second baflie plate 34 supported on the adjustable rods 33. These rods are adjustable in the vertical direction to vary the opening between the inlet member 17 and the plate 34. I have found that by varying the opening and thus varying the flow of fluid through the inlet of the pump housing, I am able to vary the rate of movement of the piston from its biased position to its operating position without affecting the pressure head developed by the pump 12. Since the bailie plate 34 is free to move in a vertical direction away from the inlet member 17 when the fluid passes back through'the pump and through the inlet and oil tube 15 to the upper side of the piston, free flow of fluid from the oil tube is not interfered with by-the baflie plate.

The piston has mounted thereon the four push rods 39 supporting the cross-head 40 which carries the work-engaging member 41. These push rods pass through bushings 39', shown in Fig. 3 mounted in the bracket member 16.

In operation when the electric motor 35 is energized fluid is drawn down through the, inlet member 17 and oil tube 15 to the inlet 14 of the pump housing. The rate of flowis dependent upon the opening between the plate 34 and inlet member 17. The fluid enters the impeller 12 through the openings 19 and 20 and is forced out through the exhaust passage 24 to the exhaust opening 26. In response to the pressure developedthe plate 27 moves away from the exhaustpassage 26 against the bias of spring 28. This permits the flow of oil to the under side of the piston and in response to the pressure there developed, moves the piston 11 from the biased position shown, to an upper position. As has been pointed out, by varying the opening between.

the inlet member 17 and the baffle plate 34, the

. amount of fluid per unit of time forced from the upper side of the piston to the under side of piston may be varied. This varies the rate of movement from the biased position to the upper position. This, however, does not affect the pres sure head developed by the pump.

By increasing the distance between the inlet member 17 and the bafiie plate 34, the quantity of fluid which can be pumped through the pump housing to the under side of the piston is in= creased, thereby increasing the rate of movement of the piston during the power stroke.

By decreasing the distance between the inlet member 17 and the bafile plate 34 the quantity of fluid is decreased and hence the rate of movement of the piston from its biased position to its operating position is decreased.

When the motor 35 is deenergized the piston returns to its biased position. When the pressure developed by the pump falls off as the impeller and motor come to rest, the baffle plate 27 returns to its partially closed position and retards the flow of oil from the under side of the piston back through the pump through the oil inlet tube 15 to the upper side of the piston. By increasing the opening between the baflie plate 27 and exhaust passages, the flow of fluid back through the pump is increased and thereby the rate of movement from its operating position to its biased position is increased. By decreasing this opening the rate of movement is decreased. Since the baflie plate 34 is free to move away from the inlet 17,

the free flow of fluid from the intake side of the pump is not interfered withv and the rate of movement of the piston to biased position is controlled only by the baffle plate 27.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the different conditions in its use and I, therefore, aim to cover by the appended claims all modifications within the true spirit and my invention.

What I claim as new and desire to secure by Letters; Patent of the United States, is,-

1. A hydraulic operating mechanism, including a casing for containing a fluid, a piston iherein scope of of said positions, apump iin said casing having intake and exhaust passages communicating with opposite sides of the piston for forcing .fluid from one side of said piston to the other side of said piston to move said piston from the biased position to another position, said pump being adapted to permit a reverse flow of fluid therethrough when said piston returns from said other position to said biased position,- and means cooperating with the iniake of said pump to control the flow of fluid to said pump whereby the rate of movement of said piston from said biased position to said other position may be retarded saidmeans cooperating with said intake permitting a free flow of fluid from said intake when said piston returns from said other position to said biased position.

2. A hydraulic operating mechanism, includinga casing for containing fluid, a piston therein movable between two positions and biased to one of said positions, an impeller pump in said casing having intake and exhaust passages communicating with opposite sides of the piston for pumping fluid from one side of said piston to the other side of said piston to move said piston from the biased position to another position, and means cooperating with the intake of said pump for controlling the rate of movement of said piston from the biased position to the other position, saidrneans cooperating with said intake permitting a free flow of fluid from said intake when said piston returns from said other position to said biased position.

3. A hydraulic'operating mechanism, including a casing for containing a fluid, a piston therein movable between two positions and biased to one of said posi-ions, a pump in said casing having intake and exhaust passages communicating with opposite sides of said piston for forcing fluid from 'one side ofsaid piston to the other side of said piston to move said piston from the biased position to another/position, said pump being adapted to permit a reverse.flow of fluid iherethrough when said piston returns from said other position to said biased position, and means cooperating with the intake of said pump for restricting the flow of fluid to said intake but permittingfree flow from said intake whereby movement of said piston only from said biased position to said other position will be retarded.

4. A hydraulic operating mechanism, including a casing for oontaining' a fluid,'a piston therein movable between two positions and biased to one of saidpositions, a pump in said casing having intake'and exhaust passages communicating with opposite sides of said pis' on for forcing fluid from oneside of said piston to the other side of said" other side of the piston to control the rate of movement of said piston from its biased position to said other posiiion, and means for adjusting said cooperating means for varying the rate-of movement of saidpiston from the biased position to' said other position, said means cooperating with the intake of said pump permitting a free flow of fluid from said intake when said piston returns from said other posi ion to said biased position.

5. A hydraulic operating mechanism, including a casing forcontaining a fluid, a piston therein movable between two positions and biased to one of ,said positions, an impeller pump in said casing having intake and exhaust passages communicating with opposite sides of said piston for forcing fluid from one side of said piston to the other side of said piston to move'said piston irom the biased position to another position, a movable plate cooperating with said intake for controlling the opening to the intake to control the flow of fluid from one side of the piston to the o.her whereby the rate of movement of said piston from the biased position to said other position may be controlled, and means extending to the exterior of said casing for adjusting the position of said pla'e with respect to the intake of said pump for varying the rate of jinovement of said piston.

said movable plate permitting a free flow oi fluid from said intake when said piston moves fromsaid other position to said biased position.

6. A hydraulic. operating mechanism, including a casing to. containing a fluid, a piston therein movable between two positions and biased to one of said positions, a pump in said casing having intake and exhaust passages communicating with opposite sides of the piston for pumping fluid' from one side ofsaid piston to the other side of said piston to move said piston from the biased position to another position, id pump being adapted to permit a reverse fl w of fluid therethrough when said piston returns from said other position to said biased position, means cooperating with the intake of said pump for controlling the rate of movement of said piston from the biased position to the other position, and means cooperating with the exhaust of said pump folcontrolling the rate of movement of said piston from the other position to its biased position.

7. A hydraulic operating mechanism, including a casing'for containing a fluid, a piston therein "movablebetween two positions and biased to one 116 piston to move saidvpistor'i from the biased pmsi- 120 tion to another position, said pump being adapted to permit a reverse flow of fluid therethrough when said piston returns from said other position to said biased position, means cooperating with said intake for restricting the flow of fluid to said intake but permitting free flow from said intake whereby movement of said piston from said biased position to said other position is retarded, and other means cooperating with said exhaust for permitting free flow of fluid from said exhaust but restricting" flow to said exhaust passage whereby movement of said piston'from saidother position to said biased position is retarded.

-, 8. A hydraulic operating mechanism, including a casing for containing fluid, a piston therein movable between two positions and biased to one of said positions, a-pump in said casing having intake and exhaust passages communicating with opposite sides of said piston for forcing fluid from one side of said piston to' the other side of said returns from said other position to said biased position, and means cooperating with the intake of said pump for controlling the flow of fluid to saidpumpto control the rate of movement of said piston from said biased position to said other .positiomand other means cooperatingwith the 5 exhaust of said pump for controlling the flow of fluid back through said pump from said other side of said piston to said one side of said piston 9. A hydraulic operating mechanism, including a casing for containing fluid, a piston therein movable between two positions and biased to one of said positions, a pump in said casing having intake and exhaust passages communicating with opposite sides of said piston for forcing fluid from one side of said piston to the other side of said piston for moving said piston from the biased position to another position, said pump being adapted to permit a flow of fluid therethrough from said exhaust to said intake when said piston returns from said other position to said biased position, means cooperating with the intake of said pump for controlling the flow of fluid to said.

pump to control the rate ofmovement of said piston from said biased position to said other position, and other means cooperating with the ex;

haust of said pump for controlling the flow of fluid back through said pump from said other side of said piston to said one side of said piston when said piston returns from said other position to said biased position, means for varying the position of said means cooperating with the in? take of said pump whereby the rate of movement of said piston from its biased position to said other position may be varied, and other means for varying the position of said means cooperating with the exhaust of said pump whereby the return movement of said piston from said other position. to its biased position may be varied.

it. A hydraulic operating mechanism, including a casing for containing a fluid, a piston'in said casing movable between two positions and biased to one of said positions, an impeller pump in said casing having intake and exhaust passages communicating with opposite sides of said piston for forcing fluid from one side of said piston to the other side of said piston to move said piston from the biased position to another position, a movable baffle plate cooperating with the exhaust of said pump and biased topartially close said exhaust and movable from the partially closed position to a fully opened position in response to pressure developed by said pump when said piston moves from said biased position to the other position and movable back to the partially closed position when said piston returns from said other position to said biased position to control the flow or fluid back through said pump to control movement of said piston from said other position to said biased position, and an adjusting rod extending from said plate to the exterior of said casing for varying the partially closed position of said plate whereby the rate of movement of said piston from said other position to said biased position may be varied.

ii. A hydraulic operating mechanism, including a casing for containing a fluid, a cover for said casing, a piston in said casing movable between two positions and biased to one of said positions, an impeller pump in'said casing having intake and exhaust passages communicating with opposite sides of said piston for forcing fluid from one side of the piston to the other side of said piston to move said piston from the biased position to another position, an adjustable plate cooperating with the exhaust of said pump for controlling the flow of fluid back through said pump from said other side of said piston to said one side of said piston to control the rate or movement of said piston'from said other position to saidbiased position, an adjusting means for said plate to vary the opening between said plate and said exhaust passage whereby the rate of movement of said piston from said other position to said biased position may be varied, said adjusting means being supported by said cover and extending through said piston and cover.

12. A hydraulic operating mechanism includ-= ing a casing for containing a fluid, a. cover for said casing, a piston in said casing movable between two positions and biased to one of said positions, an impeller pump in said, casing having an intake passage extending through said piston and an exhaust passage for forcing fluid from one side of said piston to the other side of said piston for moving said piston from its biased po= sition to another position, a movable bame plate cooperating with the exhaust passage of said pump, means for biasing said plate to partially close said exhaust passage, said plate being movable to an open position in response to the pressure created by said pump when said piston is moved from its biased position to another position, said plate moving back to its partially closed position to control the flow of fluid back through said pump when said piston moves from said other position to its biased position to control the rate of movement of said piston, and an adjusting rod supported by said cover and connected to said plate for varying the,partiallylclosed position 01' said plate for varying the rate of movement of said piston from said other position to its biased position.

13. A hydraulic operating mechanism including a. casing for containing fluid, a cover for said casing, a piston in said casing movable between two positions and biased to one of said positions, a motor mounted on said cover, a pump in said casing driven by said motor and having an intake ineluding an oil tube extending through said piston and having an exhaust, said intake and exhaust communicating with opposite sides of said piston, said pump forcing fluid from one side of said piston to the other side of said piston to move said piston from the biased position to another position, said pump being adapted to permit a reverse flow of fluid therethrough when said piston returns from said other position to said biased position, a baffle plate cooperating with the exhaust of said pump for controlling the flow oi fluid through said pump to control the rate of movement of said piston from said other position to said biased position, said plate being biased to partially close said passage, an adjusting rod connected to said plate to vary the opening between said plate and the exhaust of said pump whereby the rate of movement of said piston from said other position to said biased position may be varied, said rod being supported by said cover and extending through said piston and cover to the exterior of said casing.

14. A hydraulic operating mechanism including a casing for containing fluid, a cover for said casing, a piston in said casing movable between two positions and biased to one of said positions, a motor mounted on said cover, an impeller pump in said casing driven by said motor and having intake and exhaust passages, an oil tube connected to said intake and extending through said piston, said tube and exhaust communicating with Mid opposite sides of said piston, said jpump when operating iorcingfluid irom one side of said piston to the other side of said piston for moving 'the piston from its biased position to another po- 'sition, a tiltable bathe plate cooperating with the exhaust of said pump for controlling the flow of fluid through said pump to control the rate ot movement of said piston from said other position to said biased position, and means for biasing said plate to partially close theexhaust of said pump, a rod supported by said cover and extending therethrough and through said piston and connected to said plate to vary the openinghetjween said plate and the exhaust of said pump whereby the rate of movement of said piston from I said other position to said biased position may be'varied.

15. A hydraulic operating mechanism including I a casing for containing fluid, a cover for said casing, a piston in said casing movable between two positions and biased to one of said positions, a motor mounted on said cover, a pump in said casing connected to said motor to be driven thereby, said pump having intake and exhaust passages, an oil tube extending through said piston I and connected with the intake of said pump w L said piston from said other position to said biased fill whereby fluid may be drawn from one side of said piston'through said tube and forced to the other side or said piston through said exhaustpassage to move the piston from its biased position to another position when said motor is energized to drive said pump, said pump being adapted to permit a flow oi fluid therethrough from said exhaust to said intake when said motor is deenergized and said piston returns from said other position to said biased position,[ a sleeve' concentrically mounted with respect to said pump and cooperating with the exhaust of said pump to form an annular exhaust opening, a movab baflie plate cooperating with said pump and sle ve to control said annular exhaust opening for controlling the flowot fluid through said pump to control the rate 0 movement of said piston from said other positi to said biased position, resilient means for biasing said plate to partially close said exhaust opening, an adjusting rod connected to said plate for varying the partially closed position of said plate whereby the rate of movement of position may be varied, said adjusting rod being supported by said cover and extending through said cover and said piston to engage said plate.

16. A hydraulic operating mechanism including a casing for containing a fluid, a piston therein movable between two positions and biased to one of said positions, a pump in said casing for torcing fluid from one side of said piston to the other for moving said piston from its biased position to another position, and having intake and ex v haust passages, an oil tube extending through saidpiston and connected with the intake 01' said pump, a sleeve concentrically mounted with respect to said pump and cooperating with the exhaust 0! said pump for providing an annular exhaust opening, said oil tube and exhaust openingcommunicating with opposite sides of said piston, said pump being adapted to permit a reverse flow of fluid therethroug'h when said'piston returns from said other position to said biased position, a baille plate cooperating with said oil tube to control the flow of fluid to said pump in one direction to vary, the movement of said piston from said biased position to the other position when said pump is energized, and a same plate cooperating sleeve and pump for comwith the exhaust of said pump for providing an trolling the flow oi fluid through said pump in the opposite direction to control the rate of movement of. said piston from theother position to said biased position.

1'7. A hydraulic operating mechanism including a casing for containing a fluid, a piston therein movable between two positions and biased to one of said positions, an impeller pump in said casing for pumping fluid from one side of said piston to l the other for moving the piston from its biased position to another position and having intake and exhaust passages, an oil tube extending through said piston and connected with the intake of 'said pump, a sleeve concentrically mounted with respect to said pump'and cooperating with the exhaust of said pump for providing an annular exhaust opening, said oil tube and exhaust opening communicating with opposite ,sides of said piston, a baflle plate cooperating with said oil tube tocontrol the flow of fluid to said pump,

in one direction to ,vary the rate of movement of said piston from said biasedposition to the other position, a baflie plate cooperating with said sleeve and pump for controlling the flow of fluid through said; pump in the opposite direction to control the rate of movement of said piston from the other position to said biased position,.and means for supporting said first plate adjacent said 011 tube, said supporting means being adjustable to vary the opening between said oil tube and said first plate whereby the rate of movement or said piston from the biased position to said other position may be varied.

18. A hydraulic operating mechanism including a casing for containing a fluid, a piston 11o therein movable between two positions and biased to one of said positions, a pump-in said casing for forcing fluid from one side of said piston' to the other for moving said piston from the, biased position to another position. and having intake and exhaust passages, an oil tube extending through said piston and connected with the in take of said pump, a sleeve concentrically mounted with respect to said pump and cooperating 1 annular exhaust opening, said oil tube and exhaust opening communicating with opposite sides of said piston, said pump being adapted to permit a fiowof fluid therethrough from said exhaust to said intake when said piston returns 5 from said other position to said biased position, a baflle plate cooperating .with said oil tube to control the flow of fluid through said pump in one direction to vary the rate of movement of said piston from said biased position to the other 13) position when said pump is energized, a b'aflle plate supported by said sleeve and pump and cooperating with said exhaust opening tor controlling the flow-of fluid through said pump in the opposite direction to control the rate or mov'ementor said piston from the other position to said biased position, and a rod'connected to said plate cooperating with said exhaust opening and extending to the exterior of said casing for adjusting the position of said plate with respect to ing a casing for containing a fluid, a cover for 141;

said casing, a piston therein movable between two positions and biased to one of said positions. an impeller pump in said casing for pumping fluid from one side of said pistonto the other formoving said piston from the biased position to another position and having intake and exhaust passages, an oil tube extending through said piston and connected with the intake of said pump, a motor on said cover for driving said pump, a sleeve concentrically mounted with respect to said pump and cooperating with the excontrol the rate of movement of said piston from the'other position to said biased position, means for supporting said first plate adjacent said oil tube, said means being-adjustable to vary the opening between said oil tube and said plate 'whereby the rate of movement of said piston from the biased position to said other position may be varied, and a rod supported by said cover' and connected to said second plate cooperating with said exhaust opening, said rod extending to the exterior of said casing through said cover for adjusting the position of said plate with respect to said exhaust opening whereby the rate of movement of said piston from the other position to said biased position may be varied.

LAWRENCE S., BQURST. 

